From 1982-1989, 705 infants born to HBsAg positive mothers entered the Dutch neonatal hepatitis B vaccination program and received passive-active hepatitis B immunization, according to 6 schedules, varying in time of onset vaccination, dose of hepatitis B immunoglobulin (HBlg) and type and dose of vaccine. 118 (17%) of the mothers were also HBeAg positive. This thesis describes the protective efficacy and long-term immunogenicity of passive-active hepatitis B immunization over a period of 10 years. During follow up, 9 infants became HBsAg carriers; 8, all born to HBeAg positive mothers within the first year and another child, born to an HBeAg negative mother at the age of 5 years. No evidence of emergence of escape hepatitis B mutants was found. Protective Efficacy Rate (PER) of passive-active hepatitis B immunization at 12 months follow up was 92% for the total group with no significant differences between groups starting active immunization at birth or at 3 months; groups receiving one or two doses of HBlg or groups receiving plasma-derived or recombinant vaccine. The PER at month 12 in the group with maternal HBV-DNA levels less than 150 pg/ml was 100% and significantly higher than the 68% for the group with HBV-DNA levels above 150 pg/ml. After 5 years of follow up, the group with active hepatitis B immunization starting at birth had significantly more infants with anti-HBs levels less than 10 IU/L (15%) than the corresponding group starting at 3 months (2%). Geometric Mean Titres of anti-HBs were significantly higher in the group, starting at 3 months of age with plasma vaccine than in the corresponding group receiving recombinant vaccine. This program showed that passive-active hepatitis B vaccination can be highly effective in the prevention of neonatal hepatitis B, except for children born to women with high hepatitis B viraemia. Evaluation of vaccine schedules should take into account risk assessment according to maternal HBV DNA levels. The excellent efficacy of delayed active vaccination allows incorporation of hepatitis B vaccine into the standard infant immunization programs for countries with a passive-active immunization strategy for hepatitis B. For long-term protection, dosage of recombinant vaccine with equal immunogenicity to that of plasma vaccine should be considered.

,
S.W. Schalm (Solko)
Erasmus University Rotterdam
This study has generously been supported by the Netherlands Prevention Fund and performed at the Department of Internal Medicine II of the University Hospital Dijkzigt in Rotterdam. Financial support for this thesis was kindly given by Merck Sharp & Dohme Vaccine Division, producer of HB-VAX-DNA®.
hdl.handle.net/1765/37786
Erasmus MC: University Medical Center Rotterdam

del Canho, R. (1993, December 22). Studies on Hepatitis B vaccination in neonates. Erasmus University Rotterdam. Retrieved from http://hdl.handle.net/1765/37786